Conventional shaving and grooming devices are sometimes equipped with a pivoting arrangement providing a contour following function. Contour following functions are known from other devices as well such as epilators, skin rejuvenation, wrinkle treatment and trimming devices. In some pivoting arrangements, a moving part of the shaving head is spring loaded towards an extreme angular position, so that it assumes this extreme position when it is not submitted to any external forces.
In other pivoting arrangements a moving part of the shaving head is arranged to assume a predefined resting position, e.g. a middle position, when it is not submitted to any external forces. This resting position can be spring loaded.
Such a conventional middle position pivoting arrangement is known from U.S. Pat. No. 6,301,786, and is schematically shown in FIG. 1. A pivoting member 1 is supported by a supporting member or cradle 2, allowing it to pivot around an axis A. Two (or more) spring members 3 are arranged at the base plate 4 of the supporting member or cradle 2. When the pivoting member is in an unbiased resting position, as shown in FIG. 1, both spring members 3 are preloaded against the pivoting member 1. When the pivoting member is forced out of its resting position, it will depress one of the springs further, while extending the other spring. The force of the depressed spring will now become greater than the force from the extended spring, thus offsetting the equilibrium of the springs, and creating a net force acting on the pivoting member towards the middle position.
A potential problem with such conventional pivoting arrangements is that if the two springs have, or grow to have, slightly different spring constants, the equilibrium of the springs may become permanently offset, so that the pivoting member will fail to resume its middle position after being depressed. As a result, the resting position of the pivoting member will no longer be the middle position, but a slightly angled position.